Prior known elongate structural members that are cold-formed from sheet metal, for example, by rolling, folding or pressing a metal strip, have typically been essentially channel, Z or I sectioned. That is to say, they have usually comprised a web with flanges projecting from the edges of the web. The original strip which may, for example, be steel strip coated with zinc or an alloy of aluminium and zinc, is necessarily relatively thin, say two or three millimetres thick, to render it cold-formable, but the resultant light weight structural members are suitable for use in structures subjected to relatively modest stresses. For example, they find widespread use as the structural members of wall frames and roof trusses in dwellings, sheds, small commercial buildings and the like.